KR20190000363A - Wireless power transmission method and apparatus therefor - Google Patents

Abstract

According to an embodiment of the present invention, there is provided a method of wireless power transmission of a power transmitter comprising a plurality of coils (Multi Coils), comprising: sensing a second power receiver transmitting power to a first power receiver; Determining at least one primary coil suitable for power transmission; Using the determined at least one primary coil to determine whether the second power receiver supports a shared mode protocol; And if the second power receiver supports the shared mode protocol, transmitting power to the first and second power receivers in accordance with the shared mode protocol; Wherein the shared mode protocol may be a protocol for simultaneously managing the exchange of information between the power transmitter and the plurality of power receivers.

Description

Wireless power transmission method and apparatus therefor

The present invention is directed to a wireless power transmission method and apparatus therefor.

The contactless wireless charging method is an energy transfer method that removes wires and transfers the electromagnetic energy in a way that transfers energy through the existing wire and is used as the power source of the electronic device. There are electromagnetic induction systems and resonance systems for the contactless radio transmission system. In the electromagnetic induction method, a power is transmitted by generating a magnetic field through a power transmission coil (primary coil) in a power transmission unit and placing a reception coil (secondary coil) at a position where a current can be induced. The resonance method transmits energy using the resonance phenomenon between the transmission coil and the reception coil. However, resonance mode energy coupling between coils is used by constructing the system so that the resonance frequency of the primary coil is equal to the resonance frequency of the secondary coil.

Since the sender or master that initiates / initiates communication in the power transmitter and power receive communication protocol defined in the current WPC standard is a power receiver, the power transmitter can only send a response to the request of the power receiver The power transmitter can not detect the foreign matter in the charging area (or the magnetic field area) or can not directly control the guaranteed power level at a desired timing even if the charging environment is changed.

Therefore, it is an object of the present invention to provide an efficient and stable power transmission / reception method by allowing the power transmitter to acquire status / authority as a master / a sender depending on a situation to reflect current environment / environment in real time.

According to an embodiment of the present invention, there is provided a method of wireless power transmission of a power transmitter, the method comprising: monitoring placement and removal of objects on an interface surface of the power transmitter; Performing a digital ping and receiving a response from the power receiver; Obtaining configuration information of the power receiver and generating a power transfer contract with the power receiver using the configuration information; Sending power to the power receiver based on the power transfer contract; And sending instruction information to the power receiver to initiate communication with the power receiver; . ≪ / RTI >

In addition, the indication information may be information requesting initiation of communication with the power receiver to renegotiate the power transfer contract.

The step of transmitting the power to the power receiver further includes receiving a predetermined packet from the power receiver; And the indication information may be transmitted to the power receiver as a response to the predetermined packet.

In addition, an acknowledgment (ACK) response acknowledging the request of the power receiver included in the preset packet, a Not-Acknowledge (NAK) response rejecting the request, an ND (Not-Defined) When a bit pattern for a response is respectively defined, the bit pattern of the instruction information can be defined in a pattern different from the bit pattern of the ACK response, the NAK response and the ND response.

The preset packet may include a received power packet for changing the format of the received power packet determined in the power transmission contract or a control error packet used for determining the operating point of the power transmitter. ).

In addition, the indication information may include request information that the power transmitter requests the power receiver to obtain a right to transmit a predetermined packet.

In addition, the predetermined packet may include a packet including information on a new Guaranteed Power level of the power transmitter.

The step of transmitting the power to the power receiver further includes receiving a predetermined packet from the power receiver; Wherein the indication information is transmitted to the power receiver as a response to the predetermined packet or may be transmitted within the transmission interval if the transmission interval of the predetermined packet is longer than a threshold.

The preset packet may include a received power packet for changing the format of the received power packet determined in the power transmission contract or a control error packet used for determining the operating point of the power transmitter. ).

If the bit pattern for the ACK response acknowledging the request of the power receiver included in the preset packet, the NAK response rejecting the request, and the ND response indicating that the request is invalid is respectively defined, The bit pattern of the information may be defined in a pattern different from the bit pattern of the ACK response, the NAK response and the ND response.

In addition, when the instruction information is transmitted to the power receiver as a response to the predetermined packet, the instruction information may further include response information for the predetermined packet in addition to the request information.

Also, when the instruction information is transmitted within the transmission interval of the predetermined packet, the size of the packet carrying the instruction information may be determined based on the transmission interval of the predetermined packet.

In addition, the step of transmitting the instruction information to the power receiver may be performed when a foreign object is detected on the interface surface, or when the ambient temperature is detected to be higher than a predetermined temperature.

According to another aspect of the present invention, there is provided a method of wireless power reception of a power receiver, comprising: detecting a digital ping performance of a power transmitter and transmitting a response to the detected digital ping; Transmitting configuration information of the power receiver and establishing a power transfer contract based on the configuration information with the power transmitter; Receiving power from the power transmitter based on the power transfer contract; And receiving instruction information from the power transmitter to initiate communication with the power receiver; . ≪ / RTI >

Also in accordance with another embodiment of the present invention, there is provided a power transmitter comprising: a coil assembly comprising at least one primary coil for generating a magnetic field; A power conversion unit for converting electrical energy into a power signal; And a communication and control unit for controlling communication and power transmission with the power receiver; Wherein the communication and control unit monitors placement and removal of objects on the interface surface of the power transmitter, performs a digital ping, receives a response from the power receiver, Generating configuration information of the power receiver, generating a power transfer contract with the power receiver using the configuration information, transmitting power to the power receiver based on the power transfer contract, To the power receiver. ≪ Desc / Clms Page number 7 >

According to one embodiment of the present invention, the power transmitter has the effect of dynamically and appropriately adjusting the guaranteed power level at a desired time according to the surrounding environment / situation.

Further, according to the embodiment of the present invention, full packet transmission of the power transmitter is possible without collision with the Qi communication protocol already set in the WPC standard.

Also, according to an embodiment of the present invention, there is an effect that full packet transmission of the power transmitter is possible without collision with the packet transmitted by the power receiver.

In addition, various effects according to the embodiment of the present invention will be described below in detail.

Figure 1 shows an embodiment of various electronic devices into which a wireless charging system is introduced.
2 shows a wireless power transmission / reception system according to an embodiment of the present invention.
3 is a block diagram showing a power transmission / reception method in an inductive mode.
4 shows a method of controlling power transmission in the induction mode.
5 illustrates a power transmission device according to an embodiment of the present invention.
6 illustrates a power receiver according to an embodiment of the present invention.
Figure 7 shows a frame structure for data communication during power transfer.
8 is a diagram illustrating a sync packet according to an embodiment of the present invention.
9 is a diagram illustrating a power transfer method in a shared mode.
10 is a diagram illustrating a method of controlling a wireless power transmission / reception system to which FOD extension is applied according to an embodiment of the present invention.
11 is a diagram illustrating a response timing of a power transmitter with respect to a received power packet according to an embodiment of the present invention.
12 is a diagram illustrating a power transmitter response format according to an embodiment of the present invention.
13 illustrates a power management profile of a power transmitter in accordance with an embodiment of the present invention.
14 illustrates a power transmitter and a power reception communication protocol according to Proposition A of the present invention.
15 is a diagram illustrating a power management profile of a power transmitter according to Proposition A of the present invention.
FIG. 16 illustrates a power transmitter and power reception term communication protocol according to Proposition B of the present invention.
17 illustrates 1B (Byte) data according to an embodiment of the present invention.
18 illustrates a power transmitter and a power reception communication protocol according to Proposed C of the present invention.
19 illustrates a flowchart of a power transmission / reception method according to proposal B or C of the present invention.
20 is a flow chart illustrating an embodiment according to proposal B or C when the power transmitter desires to downgrade the GP level from 15W to 10W.
FIG. 21 illustrates a full packet format transmitted by a power transmitter according to an embodiment of the present invention.
22 illustrates a response packet format transmitted by a power receiver according to an embodiment of the present invention.
23 is a flowchart illustrating a power transmission method of a wireless power transmitter according to an embodiment of the present invention.

Best Mode for Carrying Out the Invention

As used herein, terms used in the present specification are taken into consideration in considering the function of the present invention. However, this may vary depending on the intention of the person skilled in the art, custom or the emergence of a new technique. Also, in some cases, there may be a term selected arbitrarily by the applicant, and in this case, the meaning will be described in the description of the corresponding embodiment. Therefore, it is intended that the terminology used herein should be interpreted relative to the meaning of the term rather than to the nomenclature of the term, and the entire content of the specification.

Furthermore, the embodiments are described in detail below with reference to the accompanying drawings and the accompanying drawings, but are not limited or limited by the embodiments.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows an embodiment of various electronic devices into which a wireless charging system is introduced. In FIG. 1, electronic devices are classified according to the amount of power transmitted and received in the wireless charging system.

(About 5 W or less or about 20 W or less) wireless charging can be applied to mobile / portable electronic devices such as mobile phones, smart phones, smart clocks, smart glasses, and earphones, remote controllers, smart phones, PDAs and tablet PCs. For medium / small appliances such as notebook computers, robot cleaners, TVs, sound devices, vacuum cleaners and monitors, wireless charging (less than about 50 W or less than about 200 W) can be applied. (Not more than about 2 kW or less than 22 kW) are charged to a portable electronic device such as an electric car or a personal mobile device such as a kitchen device such as a blender, a microwave oven, an electric rice cooker, a wheelchair, Can be applied. The electronic devices / moving means shown in Fig. 1 may include a power receiver as described below.

Hereinafter, a low power and a mobile device will be mainly described, but this is an embodiment, and the wireless power transmission / reception method according to the present invention can be applied to the various electronic devices described above.

Wireless Power Consortium (WPC) standardizes wireless power transmission / reception technology for standardization of wireless power transmission / reception devices.

The recently developed wireless charging system can support low power transmission and reception up to about 5W. However, recently, the size of a mobile device has been increased and the battery capacity has been increased. In the case of such a low-power charging method, there is a problem that a charging time is long and efficiency is inferior and a wireless charging system supporting intermediate power transmission and reception of about 15 W to 20 W is developed . At the same time, a wireless charging system having a resonance method added to charge a plurality of electronic devices is also being developed. The present invention relates to a wireless charging system to which a resonance method is added, and is intended to propose a resonance type wireless charging transmitter / receiver that is compatible with a low-power / medium-power induction-type wireless charging transmitter / receiver.

Hereinafter, a wireless charging transmitter and a wireless charging receiver of the inductive and resonant type proposed by the present invention, a charging method and a communication protocol using them, and the like will be described. In the following, the resonant type / mode may be referred to as a shared type / mode. Also in the following the wireless power transmitter may be referred to as a power transmitter or transmitter and the wireless power receiver may be referred to as a power receiver or receiver.

2 shows a wireless power transmission / reception system according to an embodiment of the present invention.

In FIG. 2, the wireless power transmission / reception system includes a mobile device and a base station that receive power wirelessly.

The mobile device includes a power receiver that receives wireless power through a secondary coil and a load that receives and stores power received from the power receiver and supplies the received power to the device. The power receiver includes a power pick-up unit that receives a radio power signal through a secondary coil and converts the radio power signal into electrical energy, and a communication unit that communicates with the power transmitter and controls power transmission / reception (power transmission / reception) / Communications & Control Unit. The mobile device may also be referred to below as a power receiving device.

A base station is an apparatus that provides inductive power or resonant power, and may include one or more power transmitters and a system unit. The power transmitter can transmit inductive / resonant power and control power transmission. The power transmitter includes a power conversion unit for converting electric energy into a power signal by generating a magnetic field through a primary coil (s), and a power conversion unit And a communications & control unit that controls communications and power delivery. The system unit may perform other operation controls of the base station such as input power provisioning, control of multiple power transmitters, and user interface control. The base station may also be referred to below as a power transmission equipment.

The power transmitter can control the transmit power by controlling the operating point. The controlling operating point may correspond to a combination of frequency, duty cycle and voltage amplitude. The power transmitter can control at least one of frequency, duty cycle / duty ratio and amplitude of the input voltage to control the power delivered. In addition, the power transmitter may supply a constant power, and the power receiver may control the received power by controlling the resonant frequency.

The coil or coil portion may hereinafter be referred to as a coil assembly, a coil cell, or a cell, including at least one element adjacent to the coil and coil.

Induction Mode - Low Power and Mid Power

Hereinafter, a power transmission method of a power transmitter / receiver operating in an inductive mode will be described first. However, at least one of the steps included in the method or method described for the inductive mode may be used selectively or optionally in the resonant mode.

3 is a block diagram showing a power transmission / reception method in an inductive mode.

In a wireless charging system according to the present invention, wireless charging can be performed through five phases. The five steps include a selection phase, a ping phase, an identification & configuration phase, a negotiation phase, and a power transfer phase, The negotiation step in power transmission / reception of the mode may be omitted. That is, in the low power mode, the power transmission / reception is performed in four steps, and the negotiation step can be further performed in the intermediate power mode.

In the selection phase, the power transmitter monitors the contact / departure of the object with respect to the interface surface provided at the transmitter. As shown in FIG. 2, the wireless power transmitter can sense a contact of an external object by applying a power signal. In other words, the power transmitter can apply a short power signal to the primary coil, and can sense the presence of an external object by sensing the current of the primary coil generated by the power signal. The power transmitter receives the signal strength information (packet) monitored in the selection step and detects (detects) the object based on the received signal strength information to determine whether the object is a power receiver or a simple external object Or the like). For this selection, the power transmitter may further perform at least one of the following steps: a ping phase, an identification / configuration phase, and a negotiation phase.

In the step of pinging, the power transmitter may perform digital ping and wait for the response of the power receiver. A digital ping represents the application / transmission of a power signal to detect and identify a power receiver. If the power transmitter finds the power receiver, the power transmitter may extend the digital ping to the identification / configuration stage.

In the identifying / configuring step, the power transmitter can identify the selected power receiver and obtain configuration information of the power receiver, such as the maximum power amount. In other words, the power transmitter can receive the identification / configuration information, obtain information about the power receiver, and use this information to establish a Power Transfer Contract. This power transfer contract may include constraints on a plurality of parameters that characterize power transfer in subsequent power transfer stages.

In the negotiation phase, the power receiver can negotiate with the power transmitter to create an additional power delivery contract. In other words, the power transmitter may receive negotiation request / information from the power receiver, and the negotiation step may proceed only if the target receiver is identified as an intermediate power receiver in the identification / configuration step. In the negotiation phase, additional parameters such as the guaranteed power level of the power transmitter and the maximum power of the power receiver may be negotiated. If the power receiver is a low power receiver, the negotiation step may be skipped and proceed directly to the power delivery step in the identification / configuration step.

In the power delivery phase, the power transmitter provides power to the power receiver wirelessly. The power transmitter can receive control data for transmitted power and control power delivery accordingly. And the power transmitter may stop power delivery and proceed to the selection step if the limitation of the parameters according to the power transmission contract is violated during the power transmission.

4 shows a method of controlling power transmission in the induction mode.

In FIG. 4, a power transmitter and a power receiver may include a power conversion unit and a power pickup unit, respectively, as shown in FIG.

In the power transmission stage of the induction mode described above, the power transmitter and the power receiver can control the amount of power delivered by parallel communication with power transmission and reception. The power transmitter and power receiver operate at specific control points. The control point represents a combination of voltage and current provided at the output of the power receiver when power transfer is performed.

More specifically, the power receiver selects the desired control point - the desired output current / voltage, the temperature of the particular location of the mobile device, etc. In addition, the actual control point (current control point) . The power receiver can calculate the Control Error Value using the desired control point and the actual control point, and transmit it as a control error packet to the power transmitter.

The power transmitter can then use the received control error packet to set / control a new operating point - amplitude, frequency and duty cycle - to control power delivery. Therefore, the control error packet is transmitted / received at a predetermined time interval in the power transmission step. In an embodiment, the power receiver sets a control error value as a negative value when the current of the power transmitter is to be reduced, Can be set and transmitted. Thus, in the induction mode, the power receiver can control power delivery by sending a control error packet to the power transmitter.

The resonance mode described below can operate in a different manner from that in the induction mode. In the resonant mode, one power transmitter must be able to charge a plurality of power receivers simultaneously. However, when power transmission is controlled as in the induction mode described above, power transfer to additional power receivers may be difficult to control because the transmitted power is controlled by communication with one power receiver. Therefore, in the resonant mode of the present invention, the power transmitter intends to use a method of transmitting the basic power in common and controlling the amount of power received by the power receiver by controlling its own resonant frequency. However, the operation described in FIG. 4 is not completely excluded in the operation of the resonance mode, and the control of the additional transmission power may be performed by the method of FIG.

Shared mode (resonance mode)

5 illustrates a power transmission device according to an embodiment of the present invention.

In Figure 5, the power transmission equipment includes at least one of a cover covering the coil assembly, a power adapter supplying power to the power transmitter, a power transmitter transmitting wireless power, or a user interface providing power transfer progress and other pertinent information . In particular, the user interface may be optionally included or may be included as another user interface of the power transmitting equipment.

The power transmitter may comprise at least one of a coil assembly, a tank circuit (or impedance matching circuit), an inverter, a communication unit or a control unit.

The coil assembly includes at least one primary coil that generates a magnetic field, and may be referred to as a coil cell.

The impedance matching circuit may provide impedance matching between the inverter and the primary coil (s). The impedance matching circuit may cause resonance at a suitable frequency to boost the primary coil current. An impedance matching circuit in a multi-coil power transmitter may further include a multiplexer that routes the signal from the inverter to a subset of the primary coils. The impedance matching circuit may also be referred to as a tank circuit.

The inverter can convert the DC input signal to an AC signal. The inverter can be driven as a half-bridge or full-bridge to produce a pulse wave and duty cycle of adjustable frequency. The inverter may also include a plurality of stages to adjust the input voltage level.

The communication unit can perform communication with the power receiver. The power receiver performs load modulation to communicate requests and information to the power transmitter. The power transmitter can therefore use the communication unit to monitor the amplitude and / or phase of the current and / or voltage of the primary coil to demodulate the data transmitted by the power receiver. Also, the power transmitter may control the output power to transmit data using a Frequency Shift Keying (FSK) method or the like through a communication unit. To this end, the wireless charger may additionally include a current sensor to detect the receiver by detecting a change in current in the primary coil, and to detect the transmitted data of the detached receiver.

The control unit can control the communication and power delivery of the power transmitter. The control unit can control the power transmission by adjusting the above-mentioned operating point. The operating point may be determined, for example, by at least one of an operating frequency, a duty cycle and an input voltage.

The communication unit and the control unit may be provided as a separate unit / device / chipset, or may be provided as one unit / device / chipset as shown in FIG.

6 illustrates a power receiver according to an embodiment of the present invention.

In FIG. 6, the power receiver may include at least one of a user interface that provides power transfer progress and other pertinent information, a power receiver that receives wireless power, a load circuit, or a base that supports and coils the coil assembly. In particular, the user interface may be optionally included or may be included as another user interface of the power receiving equipment.

The power receiver may include at least one of a power converter, a tank circuit (or impedance matching circuit), a coil assembly, a communication unit, or a control unit.

The power converter may convert the AC power received from the secondary to a voltage and current suitable for the load circuit. As an example, the power converter may include a rectifier. Additionally, the power converter may adapt the reflected impedance of the power receiver.

The impedance matching circuit can provide a combination of power converter and load circuit and impedance matching between the secondary coils. As an embodiment, the impedance matching circuit can generate a resonance in the vicinity of 100 kHz which can enhance the power transmission.

The coil assembly includes at least one secondary coil, and may optionally further include an element that shields the metal portion of the receiver from the magnetic field.

The communication unit may perform load modulation to communicate requests and other information to the power transmitter. To this end, the power receiver may switch the resistors or capacitors to change the reflection impedance.

The control unit can control the received power. To this end, the control unit can determine / calculate the difference between the actual operating point of the power receiver and the desired operating point. And the control unit can adjust / reduce the difference between the actual operating point and the desired operating point by adjusting the reflection impedance of the power transmitter and / or requesting the operating point adjustment of the power transmitter. When this difference is minimized, optimum power reception can be performed.

The communication unit and the control unit may be provided as separate devices / chipsets, or may be provided as one device / chipset as shown in FIG.

In shared mode, the power transmitter must manage the exchange of information with one or more power receivers. To this end, the power transmitter provides a structure for communication with the power receiver, and this structure is the same as the following communication frame.

In Figure 7, the power transmitter provides a structure that provides a sequence of time slots in which each power receiver can transmit data packets. A sync pattern as shown in FIG. 7 is provided between each of the slots. The sync pattern not only separates the slots, but also serves to optimize the communication of the power receiver. In particular, the sync pattern may provide the receiver with information for collision resolution and guaranteed latency.

Figure 7 shows a frame structure for data communication during power transfer. Shared mode protocols can use two kinds of frames: slotted frames and free-format frames. The slot frame may be used by the power receiver to transmit short data packets to the power transmitter, and the free-format frame may be used for other purposes such as bi-directional larger data packet transmission and coil selection in the multi-coil transmitter.

All frames start with a sync pattern and a measurement slot, and a measurement slot can be used to measure transmit power and receive power. As an example, nine slots may be included in one slot frame. For free-format frames there are no specific format restrictions beyond the sync pattern and the measurement frame. The start bit (information) of the sync packet may indicate the beginning of the frame.

8 is a diagram illustrating a sync packet according to an embodiment of the present invention.

As shown in FIG. 8, the sync packet may include at least one of a preamble, a start bit, a response field, a type field, an Info field, and a parity bit.

The preamble includes a sequence of bits set to one. The number of bits involved can vary depending on the operating frequency. The start bit may be set to zero. The parity bit is the last bit of the sync pattern, and may be set to 1 if the bits set to 1 included in the data fields included in the sync pattern are even, and to 0 otherwise.

The response field may include the sender's response to communication from the receiver in the preceding slot. 00 indicates that the communication has not been detected, 01 indicates that the communication error has been detected, 10 indicates a Not-Acknowledgment that the communication has been correctly received, 11 indicates that the communication has been correctly received, (Acknoledge), respectively.

The type field may be set to 1 for the first sync pattern included in the frame and may be set to 0 for other sync patterns.

The Info field has a different value and meaning according to the sync pattern indicated in the Sync field. First, if the type field is 1, the info field may indicate whether the frame is a slot frame or a free-format frame. If the type field is 0, then the info field indicates whether the next slot is a slot allocated to a specific receiver, a slot temporarily provisioned to a specific receiver, ) Slot.

9 is a diagram illustrating a power transfer method in a shared mode.

In the shared mode, the power delivery method may include a selection step, an introduction step, a configuration step, a negotiation step and a power transfer step.

The selection step represents a selection step in the guidance mode as shown in Fig. 3, and the selection step can be omitted in the shared mode and can be described in the remaining four steps. In the shared mode, if the presence of frequency shift keying (FSK) is detected in the power signal before the wake-up timeout, the process can proceed directly to the introduction step.

In the introduction phase, the power receiver may request a free slot to transmit CI (Control Information) packets to use in the next steps. To this end, the receiver transmits an initial CI packet. If the power transmitter responds with an ACK, the power receiver may proceed to the configuration stage. If the power sender responds with a NAK, another receiver may be undergoing the configuration or negotiation steps. Therefore, the receiver can request the free slot again. If the receiver receives an ACK, the receiver determines the location of its private slot in the frame, and then can transmit the CI packet using the slot at that location.

In the configuration phase, the power transmitter may provide a series of locked slots for exclusive use of the power receiver. This is for the receiver to proceed with the configuration step without collision. The receiver may transmit two identification data packets (IDHI and IDLO), optionally at least one proprietary data packets, and a Configuration Packet (CFG) using the fixed slots. Upon completing this step, the receiver proceeds to the negotiation step.

In the negotiation phase, the transmitter can still provide fixed slots for exclusive use of the receiver. This is also for the receiver to proceed with the negotiation phase without collision. The receiver may transmit negotiated data packets (including Specific Request (SRQ) and General Request (GRQ)) and at least one optional proprietary data packets using fixed slots. The receiver can terminate the negotiation phase by sending an SRQ / en (SRQ / End-Negotiation) packet. At the end of this step, the transmitter proceeds to the power delivery phase, where the transmitter stops providing fixed slots.

In the power transfer phase, the receiver transmits the CI packet using the assigned slot. And receives power. The power receiver may include a regulator circuit. The regulator circuit may be included in the communication / control unit described above. Through the regulator circuit, the receiver can self-regulate the reflection impedance of the receiver. That is, the receiver can adjust the reflection impedance to deliver the amount of power needed for the external load and receive excessive power or prevent overheating. In the shared mode, the transmitter may not adjust the power in response to the received CI packet according to the operation mode, so that it can be controlled to prevent the over-voltage situation in this case.

Foreign Object Detection (FOD) extensions

Hereinafter, FOD extension for detecting a foreign object that is not a wireless charging object will be described in the power transmission / reception / control method in the guidance mode described above with reference to FIG. 3 and FIG. This FOD extension can be performed in such a manner that a negotiation phase, a calibration phase, and a renegotiation phase are added to a basic system control method, as shown in FIG. The newly added steps can mainly perform a function for detecting foreign matter.

10 is a diagram illustrating a method of controlling a wireless power transmission / reception system to which FOD extension is applied according to an embodiment of the present invention. 3 and FIG. 4 may be applied to the same or similar descriptions. The following description will be focused on the differences from FIGS. 3 and 4, and redundant explanations are omitted .

Referring to Fig. 10, in the selection phase, the power transmitter may monitor the interface surface and monitor the placement and removal of objects using small measurement signals. This measurement signal should not wake up the power receiver located on the interface surface. When the power transmitter senses a foreign object on the interface surface, the power transmitter must remain in the selection phase and not provide a power signal to prevent overheating of the foreign object.

In the negotiation phase, the power receiver can negotiate with the power transmitter to fine-tune the power delivery contract. To this end, the power receiver may send a negotiation request to the power transmitter that the power transmitter can accept or reject. Also, in order to improve the ability of the initial evaluation of the presence of foreign objects, the power transmitter can compare the quality factor reported by the power receiver with its measurement (or signal). If the power transmitter detects a foreign object, it must return to the selection step.

In the calibration phase, the power transmitter can improve the ability to detect foreign objects during power transmission. In particular, the power transmitter can adjust the parameters of the power loss method. Here, the power receiver can provide its received power under two load conditions.

In the power transfer phase, the power transmitter can continually check for new foreign objects on the interface surface. To this end, the power transmitter may use a FOD power loss method based on a calibrated power loss calculation, for example. In addition, the placement of new foreign objects can be confirmed. If the power transmitter or power receiver detects a foreign object, the power transmitter and / or power receiver must reduce the power signal or remove the power signal and return to the selection phase.

In the renegotiation phase, the power receiver can adjust the power delivery contract, if desired. If necessary, the renegotiation phase may be terminated prematurely without changing the power delivery contract.

In the calibration phase, the power transmitter must receive information from the power receiver that the power transmitter will use to improve the power loss method for the FOD. In particular, the power transmitter must receive received power information from the power receiver, and the power receiver at this time transmits the received power information in a light load (disconnected load) and a connected load. . If the power transmitter does not receive such received power information, it may remove the power signal and return to the selection phase. However, the power transmitter can attempt to improve the power loss method by using the received power information only when it is confirmed that there is no foreign substance.

The operation of the power transmitter in the correction step may be the same as the operation in the power transmission step, but the following operations may be added.

- If the power transmitter receives a 24-bit receive power packet with the mode field set to '001' (calibration mode for light load) and meets the received power value, it can send an ACK response. Otherwise, the power transmitter may send a NAK response.

- If the power transmitter receives a 24-bit receive power packet with the mode field set to '010' (calibration mode for connected load), and if the received power value is met, send an ACK response and You can continue. Otherwise, the power transmitter may send a NAK response.

Here, the received power packet (RPP) may correspond to a packet transmitted to the power transmitter at least once by the power receiver in the negotiation step in order to change the format of the received power packet determined in the power transfer contract. When the power transmitter transmits an ACK response to this received power packet, the format of the received power packet in the ad hoc power delivery contract may be changed based on the received power packet in which the ACK response was sent.

In the power delivery phase of a system that supports FOD extension, the power transmitter can perform the following operations.

11 is a diagram illustrating a response timing of a power transmitter with respect to a received power packet according to an embodiment of the present invention.

- If the power transmitter receives a Renegotiate Packet, the power transmitter can send an ACK response and then proceed to renegotiate.

- If the power transmitter receives a received power packet in a format different from the agreed upon format in the power transfer contract, the power signal may be removed and returned to the selection phase.

- If the power transmitter receives a 24-bit received power packet with the mode field set to '000' (calibration mode for light load), the power transmitter will send the received power packet to the transmit / A response should be sent in t_response from the time of receipt. The power transmitter may send an ACK response to the power receiver indicating that the power transfer can proceed to the current state. Alternatively, the power transmitter may send a NAK response to the power receiver indicating that the power receiver should reduce power consumption. In particular, the power transmitter may transmit a NAK response in the following cases.

1) When it is confirmed that the foreign substance is located in the magnetic field

2) If the ambient temperature is too high to continue to support the current power level

3) When operating close to limit or exceeding limit due to low coupling condition

If the power transmitter sends a NAK response, the power receiver can continue to send power to the power receiver to reduce power consumption. After a sufficient number of NAK responses have been continuously transmitted without a sufficient reduction in power level being detected, the power transmitter must terminate the power transmission.

The power receiver that received the NAK response may either reduce its power consumption or send a termination power packet with the termination power delivery code set to 0x0B (Power Transfer Restart), or the power transmitter may send a NAK response Can be solved. The power receiver may retrieve a power transmitter capability packet to determine how much power consumption level to reduce.

If the power receiver does not request a response after the received power packet (e.g., if it sends a received power packet with the mode field set to '100'), the power transmitter may request the power receiver to reduce power consumption none. Therefore, the power receiver needs to be always prepared for the power reduction triggered by the power transmitter that can be generated at any time.

If the power transmitter receives a received power packet whose mode field is set to '001' or '010', it can ignore the received power value and transmit a Not-Defined (ND) response.

If the power transmitter receives an end power transfer packet including an end power transfer code of 0x0B (power transfer restart), the power signal is removed and the presence of foreign matter , And continue the ping step within t_restart (= 500ms).

As such, the power transmitter may transmit an ACK / NAK / ND response for a specific packet transmitted by the power receiver, and the embodiment of FIG. 12 may exist as a format of the response.

12 is a diagram illustrating a power transmitter response format according to an embodiment of the present invention.

Referring to FIG. 12, the power transmitter response format may be implemented with an 8-bit size bit pattern. In particular, the ND response indicating that the ACK response indicating the request acknowledgment is '11111111', the NAK response rejecting the request is '00000000', and the ND response indicating the unrecognized or invalid request may be configured in the bit pattern format '01010101'. However, this is an embodiment only and can be configured with various bit patterns.

Since the sender or master that initiates / initiates communication in the power transmitter and power receive communication protocol defined in the current WPC standard is a power receiver, it can only transmit the response to the request of the power receiver, It is not possible to directly lower the power level at a desired timing even if a foreign substance is detected in the charging region (or magnetic field region) or the current charging environment changes and power level control is required. Therefore, as described above in the WPC standard, when the foreign substance is detected in the power transmission step of transmitting power (or when it is confirmed that the foreign matter is located in the magnetic field / charging area), the power transmitter transmits the received power packet Lt; RTI ID = 0.0 > NAK < / RTI > Thus, a solution that uses a NAK response to induce the detection of foreign matter to a power receiver to reduce the power level can be referred to as a " short-term solution ".

These short-term solutions have the following disadvantages.

First, the meaning of the NAK response may be ambiguous. Namely, in accordance with the short-term solution described above, the NAK response can be used to indicate the meaning of an implicit request for power renegotiation (or a reduction in foreign matter detection / power level) Implicit semantics) is included, the semantics of the NAK response may be multiplexed and confuse the operation of the power receiver based on the NAK response.

Also, since the power transmitter can transmit the NAK response to the power receiver only when the received power packet with the mode field set to '000' is transmitted, the power transmitter can control the power level at a certain time Lt; / RTI > In particular, since the power receiver does not expect any response from the power transmitter for the received power packet with the mode field set to '100', if the received power packet with the mode field set to '100' It is impossible to transmit a NAK response for reducing the number of NAKs. In this case, the power transmitter must defer transmission of the NAK response to reduce the power level until a received power packet with the mode field set to '000' is transmitted. As a result, electric power is constantly transmitted to the foreign object, which may cause a risk of fire or the like.

Also, according to the short-term solution, there is a disadvantage that the flexibility in adjusting the power level is low.

13 illustrates a power management profile of a power transmitter in accordance with an embodiment of the present invention.

In a short-term solution, the power receiver may assume that a power level reduction is required due to foreign matter detection or the power transmitter's environment. In particular, if 5 W was being received from the power transmitter, the power receiver may stop receiving power after receiving the NAK response. However, such a short-term solution does not provide a clear way to increase the power level again, even when the charging condition of the power transmitter is improved or the reduced power level needs to be increased again, such as removing foreign matter.

Therefore, in this specification, the problem of the short-term solution described above is prevented, and a method of adjusting the power level according to foreign matter detection is proposed more efficiently. In particular, in the present specification, the power transmitter acts as a master / sender to resume / initiate / initiate communication with the power receiver, suggesting various ways to adjust the power level immediately / efficiently depending on the situation .

Detecting foreign objects and adjusting power level according to charging environment change

A. A new bit pattern definition for RFR (Request for Renegotiation)

In one embodiment, a new bit pattern RFR may be defined for the power transmitter to request renegotiation to the power receiver, and the power transmitter may request power renegotiation to the power receiver by transmitting the RFR to the power receiver. The RFR can be composed of an 8-bit size bit pattern and can be defined as a bit pattern of various 8-bit sizes except for the bit pattern defined for the ACK / NAK / ND response in the standard. For example, the RFR may be defined as '00001111', '11110000', '10101010', '10110110', '00110011', or '01001001'. However, in order to classify a bit pattern only by bit decoding, it may be desirable to define an RFR so that bit patterns can be distinguished even if only 3 bits are decoded.

The newly defined RFR may be used to indicate a transmit power renegotiation request. The power receiver receiving this RFR may send the renegotiated packet to the power transmitter and the power transmitter may transmit the ACK / NAK / ND response to the renegotiated packet. If the power transmitter has sent an ACK response, the power transmitter and power receiver may enter the renegotiation phase.

In the renegotiation phase, the power receiver may inquire Guaranteed Power (GP) of the power transmitter, and the power transmitter may respond to the power level available to the current power receiver as a GP in response thereto. If the power receiver requests the power transmitter via a specific request packet for the GP, the power transmitter may transmit an ACK response thereto to establish a new power contract with the power receiver.

As a concrete example, it can be assumed that the power transmitter and the power receiver have entered into a power transfer phase with a power transfer contract at a level of 15W. During the power transfer phase, the power transmitter detects an abnormality in the surrounding environment, such as when the power transmitter is transmitting power (or charging the power receiver), such as when the temperature rises or a foreign object is detected, If so, the power transmitter can send the RFR as a response to the received power packet of the power receiver. The power receiver receiving the RFR may send a renegotiated packet requesting power contract renegotiation to the power transmitter, which may enter the renegotiation phase by sending an ACK response thereto. In the renegotiation phase, the power transmitter and the power receiver can re-enter the power contract with a new GP level of 10 W, which the power transmitter desires.

14 illustrates a power transmitter and a power reception communication protocol according to Proposition A of the present invention. Particularly, FIG. 14A illustrates a communication protocol when the power transmitter receives the received power packet RPP. FIG. 14B illustrates a case where the power transmitter receives a control error (CE) packet Lt; / RTI > Where the control error packet indicates a particular packet used to control the operating point of the power transmitter. The box marked in this figure as hatching represents the step carried out by the power transmitter and the other box represents the step carried by the power receiver, respectively.

Referring to FIG. 14, the power receiver may first transmit the RPP or CE packet to the power transmitter. At this time, if it is determined that it is necessary to change the power transmission contract with the power receiver at the negotiation stage (or to change / adjust the GP level) according to the current situation detected by the power transmitter, The requesting RFR may be transmitted to the power receiver. The power receiver may enter the renegotiation phase to adjust / change the GP level with the power transmitter by sending the renegotiated packet to the power transmitter.

In the renegotiation phase, the power receiver may transmit a GRQ (General Request) / cap packet to the power transmitter to receive the capability packet of the power transmitter including the (maximum) GP level information information that the power transmitter is currently capable of transmitting. In response to the GRQ / cap packet, the power transmitter may transmit a Power Transmitter Capability (PTC) packet containing its power capability information to the power receiver. The PTC packet includes, as power transmission capability information, power class information of the power transmitter, GP level information (maximum / new) of the power transmitter determined in consideration of the current circumstance / condition, and / (Maximum / new) GP level information may be included.

As a response to the PTC packet, the power receiver may send an SRQ / gp packet containing the GP level information it requests to the power transmitter. The SRQ / gp packet may correspond to an SRQ packet whose request parameter field is set to indicate a 'Guaranteed Power Value', and the power receiver may define a desired / requested GP level in units of 0.5W .

If such a SRQ / gp packet allows the power receiver to accommodate the desired / requested GP level, the power transmitter may send an ACK response as a response to the SRQ / gp packet.

As a response to this ACK response, the power receiver may send an SRQ / en packet to the power transmitter indicating the end of the (re) negotiation phase. The SRQ / en packet may correspond to an SRQ packet having a 'change count' set in the request parameter field. The power transmitter may terminate the negotiation / renegotiation phase of the power transmission / reception period by transmitting an ACK signal if the change count value calculated by the power transmitter and the change count value listed in SRQ / en match after receiving the SRQ / en packet And further, in order to send and receive power to the negotiated GP level in the negotiation / renegotiation phase, the power transmitter and receiver may enter the power delivery phase.

In order to successfully terminate the negotiation / renegotiation phase, the differential parameter count values in the negotiation / renegotiation phase calculated by the power transmitter and the power receiver, respectively, must match each other. More specifically, if the power sender did not send an ACK response for both the SRQ packet and the FOD status packet with the request value set to 0x02 (i.e., the received power packet type) at the beginning of the negotiation / renegotiation phase, .

Otherwise, the power transmitter must ensure that the change count value received via the SRQ packet matches the number of different parameters between the active power transfer contract and the temporary power transfer contract. If the two match, the power transmitter must send an ACK response. Thereafter, the power transmitter may copy the temporary power transfer agreement to the active power transfer agreement and proceed to the correction step. Otherwise, the power transmitter may copy the active power transfer contract into a temporary power transfer contract, send a NAK response, and maintain the negotiation / renegotiation phase.

15 is a diagram illustrating a power management profile of a power transmitter according to Proposition A of the present invention.

Following Proposition A, the power transmitter has the effect of dynamically adjusting the GP appropriately at a desired point in time, depending on the situation. In particular, in the short-term solution described above, only the reduction of the GP level was possible, but in the case of the proposal A, the effect of not only reducing the GP level but also increasing it is possible. As a result, the power transmitter of the proposal A has an advantage that a more flexible power management profile can be implemented according to the present charging condition as shown in FIG.

Proposal B. Define a new bit pattern for RFC (Request for Communication) or RFS (Request for Sender)

In another embodiment, a new bit pattern RFC or RFS for requesting communication with the power receiver (or requesting status acquisition as a Master / Sender to resume / initiate / initiate communication) And the power transmitter can resume / initiate communication with the power receiver by sending an RFC or RFS to the power receiver. The RFC or RFS may be composed of an 8-bit size bit pattern and may be defined by various 8-bit size bit patterns except for the bit pattern defined for ACK / NAK / ND response in the standard. For example, the RFC or RFS may be defined as '00001111', '11110000', '10101010', '10110110', '00110011', or '01001001'.

This proposal B has the effect of providing an extended Qi protocol by allowing full packet transmission of the power transmitter without collision with the Qi communication protocol already set in the WPC standard.

Looking at a specific communication protocol according to proposal B, the power transmitter may first transmit an RFC or RFS to a power receiver as a response to a particular packet (e.g., a CE or RPP packet). The transmission of such an RFC or RFS may be interpreted to mean requiring the power receiver to approve of the status / authority acquisition as master / sender capable of transmitting (full) packets (powerfully). That is, if the power transmitter wishes to acquire status / authority as a master / sender capable of transmitting (full) packets from the power receiver (or initiating transmission of packets) Lt; / RTI > The power receiver may send an ACK response to the power transmitter as a response to the RFC or RFS if it grants the authority to obtain full power transmission of the power transmitter. The power transmitter receiving the ACK response may send a (full) packet to the power receiver. The power receiver may transmit an ACK / NAK / ND or a specific packet requested by the power transmitter in response to a full packet.

The communication protocol with the power receiver initiated / driven by the power transmitter may be terminated if the power receiver receives a NAK or ND response, or if there are no more packets to send to the power receiver.

The power transmitter can then resume / initiate / initiate communication with the power receiver using RFC or RFS. Therefore, if the power transmitter needs to change the power transmission contract with the power receiver depending on the surrounding environment, such as the detection of foreign matter, it can acquire status / authority as master / sender using RFC or RFS, full packet to the power receiver to negotiate / adjust it efficiently.

FIG. 16 illustrates a power transmitter and power reception term communication protocol according to Proposition B of the present invention. The box marked in this figure as hatching represents the step carried out by the power transmitter and the other box represents the step carried by the power receiver, respectively. The description of each step described above with reference to FIG. 14 can be similarly applied in connection with this drawing. Hereinafter, differences from FIG. 14 will be mainly described, and redundant description will be omitted.

Referring to FIG. 16, a power transmitter may receive a CE (or RPP) packet from a power receiver and send an RFC or RFS to a power receiver as a response thereto. If the power receiver accepts the request according to RFC or RFS, it can send an ACK packet to the power transmitter. Next, the power transmitter can transmit a PTC packet including its power transmission capability information to the power receiver, and can enter / return to the negotiation / renegotiation phase with the power receiver. The description related to packet transmission / reception in the negotiation / renegotiation phase is as described above with reference to FIG.

Proposed C. Define a new bit pattern for RFC (Request for Communication) or RFS (Request for Sender) combined with ACK / NAK / ND response

As another example, a proposal C may be proposed that redefines an RFC or RFS in the form combined with an ACK / NAK / ND response. RFC or RFS here refers to a new bit pattern for requesting communication (or requesting status acquisition as a Master / Sender to resume / initiate / initiate communication) as described in Proposal B above. However, the RFC or RFS in this embodiment may be defined in a form combined with an ACK / NAK / ND response and may be defined in the form of a joint-encoded bit pattern. For example, an RFC or RFS coupled (or jointly encoded) with an ACK response may perform the function of requesting the power transmitter to acquire status as master / sender of the power transmitter while accepting the request of the power receiver.

For example, an RFC or RFS in combination with an ACK / NAK / ND response can be defined with a new bit pattern as follows:

- '11110000': Indicates RFC / RFS combined with ACK response

- '00001111': Indicates RFC / RFS combined with NAK response

- '01010000': Indicate RFC / RFS combined with ND response

- '01011111': Requests to release status as master / sender (or instructs termination of communication)

In addition, an RFC or RFS in combination with an ACK / NAK / ND response may be signaled / encoded (e.g., tabulated and defined by content) in various embodiments and may be provided between the power transmitter and the power receiver It can be promised in advance.

The motivation derived from this proposal is to extend the Qi protocol by allowing the power transmitter to transmit full packets without collision with the Qi communication protocol already set in the WPC standard.

In this embodiment, the power transmitter may transmit an RFC or RFS combined with an ACK / NAK / ND response in response to a particular packet transmitted by the power receiver. Here, a specific packet may mean a predetermined packet that does not require or require a response of the power transmitter as shown below.

- Examples of packets that require power transmitter response: SRP (Specific Request Packet), RPP

Examples of packets that do not require the power transmitter's response: CE packets

According to the present embodiment, it is possible to support a specific function / application (e.g., an authentication protocol) that requires bilateral communication between a power transmitter and a power receiver.

The power transmitter and the power reception communication protocol according to the proposal C will be described in detail as follows. In the communication protocols proposed below, it is assumed that the power receiver is set as a master / sender that is responsible for communication (or mainly transmits a full packet), as set forth in the Qi protocol of the WPC standard . Hereinafter, the RFC or RFS combined with the ACK / NAK / ND response will be abbreviated as 'RFC or RFS' for convenience of explanation.

First, if the power transmitter wishes to be the master / sender, it may request an authorization by sending an RFC or RFS to the power receiver. This may be referred to as a collision avoidance mechanism. Specifically, the power transmitter may be used as a response to a packet requiring a response from the power transmitter, or as a response to a packet (e.g., a CE packet) transmission interval / period sufficient to transmit an RFC or RFS RFC or RFS may be transmitted within the corresponding transmission interval / period. In the latter case, there is an effect that a collision between a packet transmitted by the power receiver and the RFC or RFS can be prevented in advance.

If the transmission interval / period between packets becomes longer as in the latter case, it may correspond to a case where a CE packet is mainly transmitted. According to the predefined WPC standard, the power receiver stabilizes the shaken rectified voltage upon entry to the initial power transfer stage, and transmits the CE packet in a short period (for example, 32 ms) to quickly reach the operating point To the power transmitter. That is, the period / interval (less than the predetermined time) at which the CE packet is transmitted (for example, about 32 ms) means that the power transceiver is not in a stabilized state, and the transmission period / (E.g., more than a predetermined time) (e.g., about 250 ms) may indicate that the power transceiver is in a stable state. Accepting the master / transmitter status of the power transmitter in an unstable state can lead to confusion in communication between the power transmitter and the power receiver, both of which can operate unsteadily. Therefore, the power transmitter according to the proposal C can transmit the RFS or the RFC to the power receiver within the CE packet transmission interval only after confirming that the self and the power receiver are stable as the period / interval in which the CE packet is transmitted becomes sufficiently long. This can be interpreted that the packet transmission of the power receiver takes precedence over the packet transmission of the power transmitter, or the master / transmitter status of the power receiver takes precedence over the master / transmitter status of the power transmitter. According to this embodiment, the collision between the RFC or RFS and the CE packet is prevented, and the power transceiver can perform communication in a stable state.

Next, if the power receiver grants acquisition of status as master / sender of the power transmitter, an ACK response may be sent in response to the RFC or RFS.

The power transmitter receiving the ACK response may transmit a full packet for communicating with the power receiver, reporting that it has acquired status as a master / sender. For example, as described above, a full packet including information (for example, power transmission capability information of the power transmitter) for negotiating / renegotiation of a power transmission contract preejudged based on foreign matter detection, Receiver.

The power receiver may transmit an ACK / NAK / ND or a specific packet requested by the power transmitter in response to a full packet. The power receiver may transmit an ACK / NAK / ND or a specific packet requested by the power transmitter in response to a full packet.

The communication protocol with the power receiver initiated / driven by the power transmitter may be terminated if the power receiver receives a NAK or ND response, or if there are no more packets to send to the power receiver.

In the case where the power receiver is transmitting a CE packet, the size of the RFC, RFS and / or (full) packet that the power transmitter wishes to transmit in the interval / period between CE packet transmissions is based on the interval / ≪ / RTI > For example, assuming that the maximum interval / period between CE packets is 250 ms, the size of the RFC, RFS, or (full) packet is limited to 4B (= payload 3B + checksum 1B) .

17 illustrates 1B (Byte) data according to an embodiment of the present invention.

Referring to FIG. 17, 3Bits (start, parity, and stop bits) of 1B data may be added to form a total of 11 bits. Therefore, assuming that the bit size of RFC, RFS or full packet of size 4B can be determined as 44 bits in total, and that a transmission time of 5 ms is required per bit, a transmission time of 44 bits RFC, RFS or (full) Is 220ms or less in total and 250ms or less.

In other words, the RFC, RFS, or full packet transmitted by the power transmitter is sized (e.g., 44 bits) to be transmitted within the maximum time interval (e.g., 250 ms) The collision with the packet can be prevented as much as possible.

18 illustrates a power transmitter and a power reception communication protocol according to Proposed C of the present invention. The box marked in this figure as hatching represents the step carried out by the power transmitter and the other box represents the step carried by the power receiver, respectively. The description of each step described above with reference to FIGS. 14 and 16 can be similarly applied in connection with this drawing. Hereinafter, differences from FIGS. 14 and 16 will be mainly described, and redundant description will be omitted.

Referring to FIG. 18, the power transmitter may receive the RPP (or CE) packet from the power receiver and send the RFC or RFS to the power receiver as a response thereto. If the power receiver accepts the request according to RFC or RFS, it can send an ACK packet to the power transmitter. Next, the power transmitter can transmit a PTC packet including its power transmission capability information to the power receiver, and can enter / return to the negotiation / renegotiation phase with the power receiver. The description of packet transmission / reception in the negotiation / renegotiation phase is as described above with reference to FIGS. 14 and 16. FIG.

Meanwhile, although not shown in the figure, a packet related to security authentication may exist in addition to the above-mentioned PTC in a full packet after the power transmitter acquires status as master / sender. For example, GET_DIGESTS (a packet for requesting a digest of an authentication chain), GET_CERTIFICATE (a packet for requesting authentication), and CHALLENGE (transmitting a nonce of size-byte size) may exist.

The above-described embodiments can be equally applied to the proposal B as well. For example, the power transmitter of proposal B may also be used as a response to a packet requiring a response, or as a transmission interval / period of a packet (e.g., a CE packet) to transmit an RFC or RFS If it is long enough, it can transmit RFC or RFS within the corresponding transmission interval / period. In addition, the power transmitter of proposal B may also lose its status / authority as master / sender based on the above-mentioned reasons.

19 illustrates a flowchart of a power transmission / reception method according to proposal B or C of the present invention. The embodiments described above in connection with the flowchart can be applied to the same or similar elements, and duplicate descriptions are omitted. Also in this flowchart, the PRx-mastered Qi protocol, in which the power receiver is set as the master / transmitter and transmits full packets such as CE packet and RPP, as set forth in the Qi protocol of the WPC standard, do.

1. First, when the power transmitter (PTx) recognizes that there is a specific reason for it to initiate / initiate the communication protocol (for example, it either returns to the negotiation / renegotiation phase, such as detecting foreign objects, , The RFC (or RFS) for acquiring status / authority as master / sender can be transmitted to the power receiver PRx. At this time, the RFC (or RFS) may be an RFC (or RFS) in a form combined with an ACK / NAK / ND response.

2. The ACK response may be sent if the power receiver PRx acknowledges status / authority acquisition as master / sender of the power transmitter PTx, and may transmit a NAK response if rejected.

3. Upon receipt of the ACK response, the power receiver PRx acquires status / authority as master / sender so that full packet transmission is possible. At this time, a full packet is transmitted to the power receiver (PRx) in order to renegotiate the GP (or change the power transmission contract that has been concluded), a packet containing new GP information of the power transmitter (PTx) PTC or a newly defined packet). Currently, the WPC standard does not define a full packet format that the power transmitter can transmit and a packet format for the power receiver's response because the power receiver is set as the master / sender. Therefore, in the following FIG. 21, a full packet format that the power transmitter can transmit, and various response packet formats that the power receiver can transmit in FIG. 22 will be described later.

4. The power receiver PRx may send an ACK / NAK / ND response or response packet as a response to a full packet. The power receiver PRx may return to the PRx-mastered Qi protocol, which is itself the master / sender, after not receiving a packet from the power transmitter PTx for a predetermined time or transmitting a NAK / ND response. The power transmitter PTx may receive a NAK / ND response from the power receiver, or may terminate the master / sender PTx-mastered Qi protocol and return to the PRx-mastered Qi protocol if there is no more packet to transmit. Alternatively, the power transmitter may transmit a full packet if it receives an ACK response from the power receiver. The power transmitter may also receive an ACK / NAK / ND response or response packet as a response thereto.

20 is a flow chart illustrating an embodiment according to proposal B or C when the power transmitter desires to downgrade the GP level from 15W to 10W. With respect to this flowchart, it is assumed that the GP level has been determined to be 15W according to the power transmission contract last concluded with the power transmitter and the power transmitter is currently transmitting power to the power receiver at 15W. In addition, the description described above with reference to FIG. 19 in connection with this flowchart can be applied equally / similarly, and redundant description will be omitted.

1. First, the power transmitter (PTx) recognizes the reason for newly negotiating the GP level with the power receiver, such as detecting foreign matter in the charging area, while the power is being transmitted at a level of 15W. In this case, the power transmitter may send an RFC (or RFS) to the power receiver PRx to obtain status / authority as master / sender. At this time, the RFC (or RFS) may be an RFC (or RFS) in a form combined with an ACK / NAK / ND response.

2. The ACK response may be sent if the power receiver PRx acknowledges status / authority acquisition as master / sender of the power transmitter PTx, and may transmit a NAK response if rejected.

3. Upon receipt of the ACK response, the power receiver PRx acquires status / authority as master / sender so that full packet transmission is possible. The power transmitter PTx may transmit a full packet containing the new GP level (e.g., 10W) information downgraded at 15W to the power receiver PRx for reasons such as foreign matter detection and the like.

4. If the power receiver PRx accepts the newly proposed GP level (e.g., 10W) via a full packet, it may send an ACK response to the power transmitter PTx. This may result in a power transfer contract for the downgraded new GP level.

FIG. 21 illustrates a full packet format transmitted by a power transmitter according to an embodiment of the present invention. In particular, the (full) packet of FIG. 21 illustrates a GP packet in which the power transmitter newly includes the GP level information with which it wants to contract with the power receiver.

Referring to FIG. 21, 2 bits of the GP packet are set to a spare bit (or header, 0x01), and the remaining 6 bits can be set to a field indicating a new GP level requested by the power transmitter. At this time, the field (6 bits) may be defined to indicate a new GP level / value in a specific level / value unit (for example, 0.5 W unit).

The power transmitter may set the field to a specific value by considering / contemplating the current circumstance / environment. For example, if the temperature of the power transmitter exceeds a predetermined temperature, the power transmitter may set the field value to a GP level lower than the GP level negotiated in the previous power transfer agreement with the power receiver. If the temperature of the power transmitter is lowered to a predetermined temperature or lower depending on the surrounding situation / environment, the power transmitter may again raise the GP level of the corresponding field.

22 illustrates a response packet format transmitted by a power receiver according to an embodiment of the present invention.

Referring to Fig. 22, the response packet format of the power receiver may be defined / the same as / similar to the response packet format of the power transmitter (see Fig. 12). That is, the ND response indicating that the ACK response acknowledging the request of the power transmitter is '11111111', the NAK response rejecting the request is '00000000', and the ND response indicating that it is an unrecognizable or invalid request may be configured in bit pattern format '01010101' have. However, this is an embodiment only and can be configured with various bit patterns.

At this time, the header size of the response packet may be set differently for each response type. For example, the header size of the ACK response packet may be set to 0x06, the header size of the NAK response packet may be set to 0x07, and the header size of the ND packet may be set to 0x08.

23 is a flowchart illustrating a power transmission method of a wireless power transmitter according to an embodiment of the present invention. The embodiments described above in connection with the flowchart can be applied to the same or similar elements, and duplicate descriptions are omitted.

First, the power transmitter may perform a selection step to monitor the placement and removal of objects on the interface surface of the power transmitter (S2310).

Next, the power transmitter may perform digital ping, receive a response from the power receiver, and recognize the placement on the interface surface of the power receiver (S2320).

Next, the power transmitter can acquire the configuration information of the power receiver and generate the power transmission contract with the power receiver using the configuration information (S2330). At this time, the configuration information may include information on the power receiving capability of the power receiver, such as the maximum GP level information receivable by the power receiver. The power delivery contract may include GP level information determined by the power transmitter in consultation with the power receiver.

Next, the power transmitter may transmit a certain level of power to the power receiver based on the established / generated power transfer agreement with the power receiver (S2340). More specifically, the power transmitter may transmit power to the power receiver at a specific level determined according to GP level information included in the power transfer agreement.

Next, the power transmitter may transmit indication information for initiating communication with the power receiver to the power receiver (S2350). This instruction information transmission step may be performed when a foreign object is detected on the interface surface or when the ambient temperature is detected to be higher than a predetermined temperature.

In one embodiment, the indication information may be information requesting initiation of communication with a power receiver to renegotiate a power transfer contract. For example, the indication information may correspond to the RFR described above in connection with proposal A above. If the bit pattern for the ACK response acknowledging the request of the power receiver included in the preset packet, the NAK response rejecting the request, and the ND response indicating that the request is invalid, respectively, Can be defined in a pattern different from the bit pattern of the ACK response, NAK response, and ND response.

Although not shown in this flowchart, the step of transmitting the power to the power receiver further comprises receiving a predetermined packet from the power receiver, wherein the indication information is transmitted to the power receiver as a response to a predetermined packet . The preset packet may include a received power packet for changing the format of the received power packet determined in the power transfer contract or a Control Error Packet used for determining the operating point of the power transmitter, .

In another embodiment, the indication information may include request information that the power transmitter requests the power receiver to obtain a right to transmit a predetermined packet. For example, the indication information may correspond to RFC or RFS described above. This is as described above in connection with Proposition B above. The predetermined packet may include a packet including information on a new Guaranteed Power level of the power transmitter.

Although not shown in the flowchart, the step of transmitting the power to the power receiver may include receiving a predetermined packet from the power receiver, wherein the indication information includes power Or may be transmitted within the transmission interval if the transmission interval of the predetermined packet is longer than the threshold. The preset packet corresponds to a received power packet for changing the format of the received power packet determined in the power transfer contract or a Control Error Packet used for determining the operating point of the power transmitter . If the bit pattern for the ACK response acknowledging the request of the power receiver included in the preset packet, the NAK response rejecting the request, and the ND response indicating that the request is invalid are respectively defined, , A NAK response, and a bit pattern of the ND response.

When the instruction information is transmitted to the power receiver as a response to the predetermined packet, the instruction information may further include response information for the predetermined packet in addition to the request information. This is as described above with reference to Proposal C above.

When the instruction information is transmitted within the transmission interval of the predetermined packet, the size of the packet carrying the indication information may be determined based on the transmission interval of the predetermined packet. This is as described above with reference to FIG.

Although the drawings have been described for the sake of convenience of explanation, it is also possible to combine the embodiments described in the drawings to design a new embodiment. In addition, the present invention is not limited to the configuration and method of the embodiments described above, but the embodiments described above may be modified such that all or some of the embodiments are selectively combined .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It should be understood that various modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Various embodiments have been described in the best mode for carrying out the invention.

The present invention can be applied to various wireless charging techniques.

Claims (15)

A method of wireless power transmission of a power transmitter,
Monitoring placement and removal of objects on an interface surface of the power transmitter;
Performing a digital ping and receiving a response from the power receiver;
Obtaining configuration information of the power receiver and generating a power transfer contract with the power receiver using the configuration information;
Sending power to the power receiver based on the power transfer contract; And
Sending instruction information to the power receiver to initiate communication with the power receiver; / RTI > The method according to claim 1,
Wherein the indication information is information requesting initiation of communication with the power receiver to renegotiate the power transfer contract. 3. The method of claim 2,
Wherein the step of transmitting the power to the power receiver comprises: receiving a predetermined packet from the power receiver; Lt; / RTI >
Wherein the indication information is transmitted to the power receiver as a response to the predetermined packet. The method of claim 3,
An acknowledgment (ACK) response acknowledging the request of the power receiver included in the preset packet, a Not-Acknowledge (NAK) response rejecting the request, and an ND (Not-Defined) response indicating that the request is invalid Respectively, are defined,
Wherein the bit pattern of the indication information is defined in a pattern different from the bit pattern of the ACK response, the NAK response and the ND response. 5. The method of claim 4,
The preset packet includes a received power packet for changing the format of the received power packet determined in the power transfer contract or a Control Error Packet used for determining the operating point of the power transmitter Wherein the wireless power transmission method comprises: The method according to claim 1,
Wherein the indication information includes request information that the power transmitter requests the power receiver to obtain an authorization to transmit a predetermined packet. The method according to claim 6,
Wherein the predetermined packet includes a packet including information on a new Guaranteed Power level of the power transmitter. The method according to claim 6,
Wherein the step of transmitting the power to the power receiver comprises: receiving a predetermined packet from the power receiver; Lt; / RTI >
The instruction information includes:
Transmitted to the power receiver as a response to the pre-established packet, or
And when the transmission interval of the predetermined packet is longer than the threshold, the transmission is performed within the transmission interval. 9. The method of claim 8,
The preset packet includes a received power packet for changing the format of the received power packet determined in the power transfer contract or a Control Error Packet used for determining the operating point of the power transmitter Wherein the wireless power transmission method comprises: 9. The method of claim 8,
If a bit pattern for an ACK response acknowledging the request of the power receiver included in the preset packet, a NAK response rejecting the request, and a ND response indicating that the request is invalid are respectively defined,
Wherein the bit pattern of the indication information is defined in a pattern different from the bit pattern of the ACK response, the NAK response and the ND response. 9. The method of claim 8,
When the indication information is transmitted to the power receiver as a response to the predetermined packet,
Wherein the indication information further includes response information for the predetermined packet in addition to the request information. 9. The method of claim 8,
When the instruction information is transmitted within the transmission interval of the predetermined packet,
Wherein a size of a packet carrying the instruction information is determined based on a transmission interval of the predetermined packet. The method according to claim 1,
Wherein the step of transmitting the indication information to the power receiver comprises:
When a foreign object is detected on the interface surface or when the ambient temperature is detected to be higher than a predetermined temperature. A method for wireless power reception of a power receiver,
Detecting a digital ping performance of the power transmitter and transmitting a response to the detected digital ping;
Transmitting configuration information of the power receiver and establishing a power transfer contract based on the configuration information with the power transmitter;
Receiving power from the power transmitter based on the power transfer contract; And
Receiving instruction information from the power transmitter to initiate communication with the power receiver; / RTI > In a power transmitter,
A coil assembly comprising at least one primary coil generating a magnetic field;
A power conversion unit for converting electrical energy into a power signal; And
A communication and control unit for controlling communication and power transmission with the power receiver; ≪ / RTI >
Wherein the communication and control unit comprises:
Monitoring the placement and removal of objects on the interface surface of the power transmitter,
Perform a digital ping, receive a response from the power receiver,
Acquiring configuration information of the power receiver, generating a power transfer contract with the power receiver using the configuration information,
Transmit power to the power receiver based on the power transfer contract,
And transmit indication information to initiate communication with the power receiver to the power receiver.

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